2.A.118 The Basic Amino Acid Antiporter (ArcD) Family
The ArcD family is a constituent of the IT superfamily (Lolkema and Slotboom, 2003; Prakash et al., 2003; Rabus et al., 1999). It is the st313/AitC family of Lolkema and Slotboom (2003). It consists of proteins from Gram-negative and Gram-positive bacteria (e.g., Streptococcus, Escherichia, Salmonella, Fusobacterium and Borrelia species). The proteins are of about 480 aas with 10-12 putative TMSs. Functionally characterized homologues are in the DcuC (TC #2.A.61) and ArsB (TC #2.A.4) families. Some members of the family probably catalyze arginine/ornithine or citruline/ornithine antiport (Gupta et al., 2013; Rimaux et al., 2013).